Tomatoes don't need darkness. The idea that plants need darkness to grow properly is mostly a myth. For garden vegetables it's a complete myth.
Tomatoes want and need as much sun as you can get them. I wouldn't even bother planting a full sized indeterminate plant if I didn't have a spot with at least 8, preferably 10 hours of direct sunlight in summer. Some of the tiny patio varieties may be able to swing 6-8 hours of sun but they'll produce much less than true full sun.
